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Alternative rendering

Kyoto ships with an ability to define own rendering, avoiding built-in html/template. To use this option, you will need to use render.Writer function, provide own rendering to io.Writer and use render template function to render a component.

This example shows how to define custom rendering for a single component and use this component in pair with classic templates.

package main

import (
    "net/http"
    "encoding/json"
    "io"

    "github.com/kyoto-framework/kyoto"
    "github.com/kyoto-framework/kyoto/render"
    "github.com/kyoto-framework/kyoto/lifecycle"
)

func ComponentUUID(core *kyoto.Core) {
    lifecycle.Init(core, func() {
        core.State.Set("UUID", "")
    })
    lifecycle.Async(core, func() error {
        resp, _ := http.Get("http://httpbin.org/uuid")
        data := map[string]string{}
        json.NewDecoder(resp.Body).Decode(&data)
        c.State.Set("UUID", data["uuid"])
        return nil
    })
    render.Writer(core, func(w io.Writer) error {
        fmt.Sprintf(w, `
            <div>
                Component UUID: %s
            </div>
        `, core.State.Get("UUID"))
    })
}

package main

import (
    "html/template"

    "github.com/kyoto-framework/kyoto"
    "github.com/kyoto-framework/kyoto/render"
    "github.com/kyoto-framework/kyoto/lifecycle"
)

func PageIndex(core *kyoto.Core) {
    lifecycle.Init(core, func() {
        core.Component("UUID1", ComponentUUID)
        core.Component("UUID2", ComponentUUID)
    })
    render.Template(core, func() *template.Template {
        return template.Must(template.New("page.index.html").Funcs(render.FuncMap(core)).ParseGlob("*.html"))
    })
}

<!DOCTYPE html>
<html>
<head>
    <title>Page Index</title>
</head>
<body>
    {{ render .UUID1 }}
    {{ render .UUID2 }}
</body>
</html>

You can use render function also with a classic templates too.
First, this function tries to find a custom rendering function. If not found, it dynamicaly resolves a component name and doing inline dynamic rendering with a classic template. In this way you can simplify your code, ommit writing a template definition name and your rendering becomes dynamic.

With render function you can avoid an error while calling other template with a dynamic name.
Wondering what I'm talking about?
Check this: https://stackoverflow.com/questions/20716726/call-other-templates-with-dynamic-name

Performance impact

In case of fallback to classic templates, render function has a huge performance impact. Please, avoid using it in high-load systems.

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